Winding machine



Aug. 29, 1961 'r. E. PITTS 2,998,203

I WINDING MACHINE Filed Oct. 5. 1958 s Sheets-Sheet 1 FIG. I

INVENTOR.

THOMAS E. PITTS Aug. 29, 1961 2 a e h V INVENTOR.

THOMAS E. PITTS Aug. 29, 1961 1-. E. PITTS 2,998,203

WINDING MACHINE Filed Oct. 5, 1958 3 Sheets-Sheet 3 FIG. 5

0 5 /-22 FIG. 6

0 .UL/ Q I |o I INVENTOR.

THOMAS E. P ITTS Patented Aug. 29, 1961 2,998,203 WINDING MACHINE Thomas E. Pitts, Cranston, R.I., assignor to Leesona Corporation, a corporation of Massachusetts Filed Oct. 3, 1958, Ser. No. 765,185 3 Claims. (Cl. 242-43.2)

The present invention relates to a winding machine and is directed more particularly to an improved drive-traverse roll adapted to operate at very high winding speeds.

In the following specification and claims it is to be understood that the term yarn is used in'a general sense to apply to all kinds of strand material, either textile or otherwise, and the designation package is intended to mean the product of a winding machine whatever its form.

It is well known in the winding art to guide a strand onto a rotating packag or package core by means of a rotatable cylindrical roll having an endless groove in the peripheral surface thereof. The roll is usually located at or near the yarn package or even in surface-to-surface driving contact with the package and rotation of the roll moves the yarn back and forth longitudinally of the package to distribute the yarn therealong. Two types of rolls are in common use: a single groove roll and a so-oalled multi-groove roll. The single groove roll is of large diameter and its periphery is formed with a single groove which extends from adjacent one end of the roll to the other and back again in a continuous path without intersecting with itself. The multi-groove roll is, in effect a single groove arrangement compressed upon a much smaller roll, the return portion of the groove being superimposed upon the forward portion so that there are one or more intersections of the two portion between their ends. Strictly speaking, there is'still only a single groove in the multi-groove roll but since it has the appearance of two distinct systems of intersecting grooves it is called multi-groove to distinguish it from the single groove roll. In either case, the yarn is engaged in the groove and is traversed to and fro longitudinally of the package as the roll rot-ates.

All multi-groove drive-traverse rolls heretofore known in the art have been limited as to speed of operation by the tension required to maintain the strand of yarn in the traversing groove. In any yarn being forcibly moved at a given point along its length, the portions of yarn on either side of this point tend to lag behind due to inertia and frictional resistance. In other words, the yarn in approaching and leaving the point at which the driving force is applied to it passes through an obtuse angle, the extent of which is due to the velocity, acceleration, resistance encountered, etc. As the strand in being traversed encounters a groove intersection, there is a tendency, due to the lag of the yarn, for the strand to leave the out- Ward-traversing branch or portion of the groove at a crossover point and to return in the direction from which 'it came rather than to complete the traversing movement.

How great this tendency is depends largely on the closeness of correspondence betweenthe lag angle and the angle of intersection of the two groove branches. Obviously, if these angles are the same, the yarn will almost inevitably be laid into the inwardly-directed branch rather than to continue outwardly. In order to overcome this tendency, tension must be maintained in the winding strand so as to keep the strand as taut as possible, and minimize the lag angle and the correspondence between this angle and the angle of intersection of the groove branches. However, as the speed of winding increases said tendency becomes stronger as the yarn lags further behind, and higher tensions are required to avoid an incomplete traverse. Now excessive tension damages the yarn and, moreover, there is always some upper limit where the tension required to maintain said strand in the proper branch of said groove exceeds the maximum tension which the yarn can sustain without breakage.

A multi-groove roll is better suited than a single groove roll for winding a package of substantial length inasmuch as an equivalent single groove roll must be of exceedingly large diameter and inordinately bulky to effectively traverse yarn on a long package and many attempts have been made during the past 25 years to improve the multi-groove roll. However, none of these resulted in any substantial increase in permissible winding speed. In view of the fact that maximum yarn speeds attainable with prior art multi-groove drive-traverse rolls ranged from 550 to 750 yards per minute, depending on denier, or yarn count, and type of yarn, it is quite surprising that these same yarns can be delivered by a drive-traverse roll constructed in accordance with the present invention at rates of from "750 to 1200 yards per minute without any increase in the tension required to maintain the winding strand in the proper branch of the traverse groove.

Hence, the principal object of the present invention is to provide an improved multi-groove traverse roll capable of operating at high speed without damage to the yarn being traversed.

Another object of the present invention is to provide a multi-groove traverse roll adapted to drive a self-supporting yarn package at high speeds while delivering the yarn to the package. A further object of the invention is to provide a multi-groove traverse roll profiled so as to establish an effective separation between intersecting grooves and reduce the likelihood of the yarn entering the improper groove.

An additional object is to provide an improved configuration of groove intersection for a multi-groove roll, which configuration facilitates the proper passage of the yarn through the intersection.

Another object of the present invention is to provide a high speed, multigroove drive-traverse roll for a winding machine which is inexpensive to manufacture and economical and durable in use.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention, accordingly, comprises the apparatus having the construction, combination of elements and arrangement of parts exemplified in the following detailed disclosure and limited as to scope only as indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following 7 detailed description taken in connection with the accompanying drawings wherein: I

FIG. 1 is a front elevation of the improved drive-roll of the present invention;

FIG. 2 is an elevation of the drive roll of FIG. 1, rotated at 180 degrees;

FIG. 3 is an angular cross-sectional view taken along the line III--III of FIG. 1;

FIG. 4 is an angular cross-sectional view similar to FIG. 3 but taken along the line IV-IV of FIG. 2;

FIG. 5 is a development of the surface of the drivetraverse roll of FIG. 1;

FIG. 6 is a schematic showing of the profiles of the bottoms of the branches of the groove in the drive-traverse roll of FIG. 1 with certain significant points being indicated by lines numerically designated in correspondence with other figures; and

FIG. 7 is an enlarged fragmentary sectional view taken along the line VIIVlI of FIG. 2.

Referring now to FIGS. 1, 2 and 5 of the drawings wherein is disclosed a preferred embodiment of the presformed from a suitable plastic such as Bakelite, or cast I or machined from metal. Roll 10 has a peripheral surface 12-, a left end 14, a right end 16, as viewed in FIGS.

1 and 2 and may be fixed to shaft 18 by means of set screws 19a and 19b.

Formed in surface 12 is a substantially continuous groove having two branches 22 and 24, respectively, branch 22 extends from point 32 adjacent end 14 helically, and clockwise as viewed from this end, to point 34 adjacent end 16. Branch 24 extends from point 32 helically, but counterclockwise as viewed from end 14, to point 34 and intersects branch 22 at a plurality of intermediate points 36, 37 and 38. Branches 22 and 24 are smoothly connected at points 32 and 34 to form one substantially continuous double groove 20 extending nearly end-to-end of roll 10. As can be best seen from FIG. 7, groove 20 is generally V-shaped in cross-section, having a very narrow fiat bottom 21 and flaring upwardly and outwardly from bottom 21 to the exterior peripheral surface 12 of the roll. It is an important feature of the invention that the cross-section of the groove is not uniform along its complete length but varies in a carefully predetermined manner both as to depth and width at certain selected spaced portions thereof.

The variation as to depth may be best understood by a consideration of FIGS. 3 and 4 showing particular portions of the groove in profile and FIG. showing a development of the profiles of the two groove branches 22 and 24 in their entirety. For convenience, point 32 will be selected as the starting point for the discussion in connection with branch 22, this being the extreme i left-hand termination of this branch. At point 32, branch 22 is quite shallow in depth but increases substantially by the time a point spaced 90 of rotation from point 32 in the directionof intersection 36. The groove grows shallower again as intersection 36 is approached until f exactly at this intersection the depth is at a minimum which is somewhat less than at point 32. Past point 36, the depth increases again until a maximum is achieved at a point spaced approximately 90 of rotation from point 36 and 270 of rotation from beginning point 32, which maximum is somewhat greater than that intermediate points 32 and 36. This depth, once achieved,

is maintained until point 34, the extreme right termination of the groove, is approached. At a distance spaced about 90 of rotation from point 34, the depth gradually decreases until at point 34 it is the same as at beginning point 32.

The course of branch 24 will now be followed from the same beginning, point 32, where it merges with branch 22, moving from left to right in a counterclockwise direction. At point 32, branch 24 has the same depth as branch 22 but increasing as point 32 is left until a maximum depth, equal to the maximum depth of branch 22, as at points 37 and 38, is achieved at a point spaced some 90 of rotation from point 32. The depth remains constant for about 180 of rotation or until point 37 is 90 of rotation distant. Then the groove becomes gradually shallower, achieving minimum depth at point 37 equal to that of branch 22 at points 36. Upon leaving point 37, the depth increases until at a point spaced roughly 90' of rotation past point 37, it is somewhat less than maximum and the same as branch 22 at a point intermediate points 32 and 36. The groove branch rises immediately from this point back to minimum depth at point 38, after which it falls off again to somewhat less than maximum after 90 of rotation but rises again to merge with the groove branch 22 at point 34. I

From a study of FIGS. 1, 2 and 5, it will be observed that each of the intersections of the two branches is of a characteristic shape by which a portion of one of the groove branches adjacent each of the intersections is distinguished from the remainder of the branch. Thus, moving along branch 22 as before from point 32, the portion of this branch which is on the opposite side of intersection from point 32 is offset from the true helical path previously followed by the branch a distance roughly equal to the normal width of the groove and, moreover, the egress opening from the intersection of this portion is substantially enlarged compared to the normal groove width but in an unbalanced, i.e., non-symmetrical fashion toward the left. In other words, at intersection 36, the portion of branch 22 directly on the opposite side of branch 24 from left roll end 14 is in the nature of a flaring mouth to facilitate reception of the yarn. The flare, however, is not equal on both sides of the axis of the branch but is almost exclusively in the direction of end 14. Thus, considering the walls which constitute the branch, the left wall, i.e., that wall toward end 14, is inclined from bottom to top toward end 14 at a considerably greater angle than was the case from point 32 to intersection 36 so that at its top extremity this wall joins the adjacent wall of branch 24 at a point spaced substantially from the center of intersection 36. On the other hand, the right wall of branch 22 maintains about the same inclination as before but is offset bodily a slight distance toward end 14. Moving away from intersection 36 and end 14, the distance between the top extremities of the right and left wall decreases, the left wall becoming less and less inclined, so that the branch, in effect, tapers back to normal configuration.

In the case of intersections 37 and 38, it is branch 24 that is offset and enlarged but in the direction of the right end of the roll, i.e., that end to which point 34 is adjacent. Thus, following branch 24 from point 34, the portion of this branch on the opposite side of intersection 38 from right end 16 is offset a distance about equal to normal groove width and is substantially en larged at its mouth, the enlargement and offset both being toward the end 16. The same is true of the portion of branch 24 on the opposite side of intersection 38 from end 16.

The high speed drive-traverse roll of the present invention operates in the following manner. A strand of yarn is drawn from a yarn supply through a yarn guide spaced from the drive-traverse roll and is attached to a package core for winding thereon. Said core is rotatably mounted on a spindle and is adapted to contact the drive-traverse roll for rotation thereby. This is conventional and is not shown in the drawings.

As drive-traverse roll 10 rotates the strand of yarn engages groove 20 and is traversed thereby longitudinally of said core to form a random wound, self-supporting package as the core rotates. 'Ihe strand of yarn is drawn through the aforementioned yarn guide and across roll it at a tangent to the bottom of groove 2i), feeding thence to the package at a point substantially at the line of contact between said roll and said package.

The manner in which the strand of yarn is caused to follow each branch 22 or 24 from end to end thereof without being diverted at the crossover points 3638 from one branch to the other and without need of excessive tension in the yarn will now be explained. Assume the strand to be engaged at point 32 and roll 10 to be rotating in the direction indicated by arrows in FIGS. 1-4, that is clockwise as viewed from right end 16.

As roll 10 notates, the strand will be urged toward right end 16 by the left wall of branch 22 and the strand will tend to lag toward left end 14. Thus, at crossover point 36 there is a tendency for the strand to engage branch 24 extending toward the left. However, this tendency is overcome by the difference in groove depths at this point and by the offset and. increased width of the branch 22 to the left at crossover 36 which allows the branch to engage the strand in a position more to the left, where a portion of the yarn is likely to be in lagging behind, than would be possible with a branch that is straight or 'of uniform width.

Further rotation of roll 10 moves the strand of yarn toward right end 16. At crossover point 37 branch 22 is at maximum depth and far below the level of branch 24 at this point. The indentation in the left wall of branch 22, caused by the intersection therewith of branch 24, is very slight as branch 24 is quite shallow at point 37. Thus, there is little tendency for the strand of yarn to be diverted into branch 24 and a strong inclination for the strand to remain in branch 22 because the exceptional depth thereof maintains an extended length of the strand in contact with branch 22 to thereby keep firm control of the strand. At crossover point 38 the situation is similar, the greater depth of branch 22 retaining the strand of yarn therein.

After two revolutions of roll the strand reaches point 34 and passes from branch 22 into branch 24. The depth of both branches at this junction is small so that snagging is prevented and precise placing of the strand on the package is obtained. The strand is then urged toward left end 14 by contact with the right wall of branch 24 and the strand tends again to lag its forced motion but now toward right end 16.

As roll 10 rotates and the strand is traversed in branch 24 to crossover point 38 where the branch is of minimum depth there is a tendency for the strand to engage branch 22 extending toward the right. However, this tendency is overcome by the offset and the increased width of branch 24 to the right, similar to the case of branch 22 at point 36 but in a different direction. At crossover point 37 the situation is similar, the offset and increased Width of branch 24 retaining the strand of yarn therein.

Further rotation of roll 10 moves the strand of yarn nearer left end 14. At crossover point 36 branch 24 is at maximum depth and far below the level of branch 22 at said point. The indentation in the right wall of branch 24 caused by the intersection therewith of branch 22, is very slight as branch 22 is quite shallow at point 36. Thus, as has been explained for the case of branch 22 at points 37 and 38, the strand is retained in branch 24 and is not likely to be diverted.

After four revolutions of roll 10 the strand has returned to point 32, having traversed groove 20 completely and the cycle repeats.

From the foregoing description, several characteristics of the roll of the invention will have been observed. First, at each intersection one groove branch is of minimum depth and the other of maximum depth to, in effect, separate the two branches from one another as much as possible. Second, on the side of the intersection in the direction of yarn travel, each groove of minimum depth is offset slightly and greatly widened but only in the direction opposite to yarn travel. It is the combination of these two characteristics that brings about time successful results of the invention, each tending to compensate for undesirable features of the other and together constituting a solution to the problem.

Up to this point, the reference to groove dimensions both laterally and radially have been in general terms. It has, however, been established that a certain relationship between these values and the dimensions of the roll as a Whole exists which has an important bearing on the results obtained. In describing this relationship, use will be made of a hypothetical unit of length R. While the exact value of R may be varied, it obviously must have some reasonable relation to the diameter of the yam, such as at least twice this diameter, although normally much greater. In terms of R, the roll diameter'shou ld be about 40R and the traverse length, i.e., the distance between points 32 and 34, 80R although there is nothing critical in this value. It is important, however, that the groove 20 have a pitch of about 40R, i.e., advance the yarn a distance generally equal to the roll diameter in 360 of rotation of the roll.

With respect to groove depth, the minimum depth, as at points 36 for branch 22 and 37, 38 for branch 24, is about R while the maximum depth, as at points 37 and 38 for branch 22 and point 36 for branch 24 is about 10R. A suitable slightly more than minimum depth, as at points 32 and 34, is 2R while a somewhat less than maximum depth, as between points 32 and 36 for branch 22 and between points 37 and 38 and points '38 and 34 for branch 24 may be 7R. These values are indicated graphically in FIGURE 6, although it will be understood that the exact scale used is selected only for illustration and is not necessarily intended to indicate a suitable actual Value for R.

With respect to groove width, the normal value is about R. The widest point in each of the enlarged groove mouths, which is ordinarily the same for all intersections, is 5R at some distance from the center of the intersection. Although not mentioned previously, the width of the groove may, and preferably does, vary other than at the mouths adjacent the intersection.

Thus, branch 22 flares from a width of approximately R at point 32 to a width of approximately 2R intermediate points 32 and 36, thereafter tapering to a width of approximately R at point 36. Branch 22 widens abruptly to approximately 5R beyond intersection to form a mouth 36 and then tapers to a width of approximately 2R at point 37. Branch 22 then flares to a width of approximately 3R intermediate points 37 and 38, next tapering to a width of approximately 2R at point 38. After flaring to a width of approximately 3R intermediate points 38 and 34, it finally tapers to a width of approximately R at point 34.

Branch 24 beginning with a Width of approximately R at point 32 flares to a width of approximately 3R intermediate points 32 and 36, thereafter tapering to a width of approximately 2R at point 36. Past intersection 37, branch 24 narrows abruptly to approximately R at point 37. Past intersection 38, branch 24 narrows abruptly to approximately R, then flares to a width of approximately 2R intermediate points 38 and 34, and finally tapers to a width of approximately R at point 34.

The foregoing dimensions are preferred for a roll of the type disclosed as they have been found to give optimum performance. However, the dimensions can be varied within some ranges and still give very substantial improvements over prior art traverse rolls. The pitch of groove 20 may be varied in the range 30R-5OR. A smaller pitch makes the winds of yarn on the package too nearly parallel so that the package will not be selfsupporting. A larger pitch increases the speed at which the'strand is traversed thereby increasing the difiiculty of controlling the strand and increasing the lagging effect.

The depth of groove 20 at end points 32 and 34 may be varied in the range R-4R. It is more diflicult for the strand of yarn to escape a deep groove but also if the groove is deep the strand tends to snag on the roll and stitch on the package. The depth of the shallow branches of groove 20 at crossover points Cad-38 may be varied in the range /2R2R. Here again, the deeper the groove the less likelihood there is of the strand escaping therefrom but the more interference with proper yarn control in the deeper crossing branch caused by the deeper notch in the side of maximum depth branch.

The depth of the deep branches of groove 28 at crossover points 3638, and in between successive crossover points where the depth remains constant, may be varied in the range 9Rl1R. Although generally the deeper this is cut the more positively it controls the strand of yarn, depths from 9R to 11R provide sufficient control to achieve a substantial increase in speed over the prior art traverse rolls, whereas further increase in depth beyond this presents serious problems in returning the strand to, or adjacent, the surface of roll 10 in those locations where the groove must be shallow.

Intermediate successive crossover points where the same branch of groove 20 is shallow, as between points 37 and 38 for branch 24, the maximum depth of the branch may be varied in the range R-9R. Intermediate an end point and the adjacent crossover point the maximum depth of the branch of groove 20 which is shallow at said crossover point, as between points 32 and 36 for branch 22, may be varied in the range 5R-9R. In both of these cases the deeper this is cut the better control is achieved over the strand of yarn but the more difficult it becomes to bring the strand back near to the surface of roll 10.

The width of groove 20 at end points 3-2 and 34 may be varied in the range /2R3R, it being necessary to increase or decrease the width at these points as the depth is increased or decreased. The width of the shallow branches of groove 20 at crossover points 36-38 may be varied in the range /2R3R on the side from which the yarn approaches the respective point, and may be varied in the range 2R7R on the opposite or mouth side. Here, the width should be appropriate to the helix angle or pitch of groove 20, the greater the pitch the wider the shallow branch past the crossover.

The width of the deep, i.e., maximum depth, portions of groove 20 at crossover points 3638 may be varied in the range /zR-3R. For yarn control purposes, it is desirable to maintain this width at a minimum but the roll becomes exceedingly difficult to fabricate as the width is decreased. Other than at the intersection, the deep portions of groove 20 may be as wide as 4R toward the ends of roll and as wide as 8R at the center thereof, the only reason for increasing the Width being ease of manufacture.

It is to be understood that although the herein described embodiment has a uniform helix and three crossover points, the drive-traverse roll of the present invention can be adapted to provide an accelerated helix and to have any number ofcrossovers. Since certain changes may, accordingly, be made without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A multi-groove yarn traverse roll having formed on the surface thereof a continuous helical groove including two branches which intersect at least three times, a first one of said branches being generally ten times the depth of the second of said branches at one intersection and said second branch being generally ten times the depth of said first branch at two of said intersections, the depth of said first branch between said two intersections being greater than its depth at said intersections but less than the depth of said second branch at and between said two intersections.

2. A multi-groove traverse roll having formed on the surface thereof a continuous helical groove including two branches which intersect at least three times, a first one of said branches being generally ten times the depth of the second of said branches at one intersection and said second branch being generally ten times the depth of said first branch at two of said intersections, the depth of said first branch between said two intersections being greater than its depth at said intersections but less than the depth of said second branch at and between said two intersections, and the shallower branches at each intersection on the side of the intersections in the direction of travel of a strand of yarn therein being offset from a true helical path and formed with an enlargement, each enlargement being generally V-shaped in plan configuration and unsymmetrical in a direction opposite to the direction of said strand of yarn therein, the direction of ofiset also being opposite to said direction of yarn traverse.

3. A multi-groove traverse roll having formed on the surface thereof a continuous helical groove including two branches which intersect at least three times, a first one of said branches being generally ten times the depth of the second of said branches at one intersection and said second branch being generally ten times the depth of said first branch at two of said intersections, the depth of said first branch between said two intersections, being greater than its depth at said intersections but less than the depth of said second branch at and between said two intersections, and the shallower branches at each intersection on the side of the intersections in the direction of travel of a strand of yarn therein being ofiset from a true helical path a distance generally equal to the normal width of said groove and formed with an enlargement, each enlargement being generally V-shaped in plan configuration and unsymmetrical in a direction opposite to the direction of said strand of yarn therein, the direction of oifset also being opposite to said direction of yarn traverse.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Nov. 26, 

